Field of the Invention
This invention relates, in general, to respirators and, in particular, to a new and useful pressure indicator for respirators which provides a pressure indication which can be sensed in darkened conditions.
Respirators with pressure gas tanks containing the ventilating gas are equipped with a pressure measuring instrument to monitor the pressure in the tanks, and thus also the supply of the ventilating gas. This monitoring must also be possible in dark rooms or in great depth in water.
A known pressure indicator for respirators contains in the same housing in addition to a pointer, another pointer admitted by the same pressure. It is a displaceable piston which is under spring pressure and which has an outwardly protruding indicating pin. The indicating pins are provided with elevations or depressions, like grooves, which correspond to the pressure stages. They can be recognized by feeling. This is also possible in the dark or under water. Since the stroke of the indicating pin is small, however, the markings are so close together that a reliable recognition is not possible, and errors cannot be excluded. This is particularly true when working with gloves (German Pat. No. 1,299,533).